Dissertations / Theses: 'Intelligent and Flexible Manufacturing'

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Fan, I.-P. "Intelligent flexible manufacturing system control." Thesis, Cranfield University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234483.

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Rogers, Paul. "Object-oriented modelling of flexible manufacturing cells." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.276540.

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Leitão, Paulo. "An agile and adaptive holonic architecture for manufacturing control." Doctoral thesis, Universidade do Porto, Faculdade de Engenharia, 2004. http://hdl.handle.net/10198/1440.

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In the last decades significant changes in the manufacturing environment have been noticed: moving from a local economy towards a global economy, with markets asking for products with high quality at lower costs, highly customised and with short life cycle. In this environment, the manufacturing enterprises, to avoid the risk to lose competitiveness, search to answer more closely to the customer demands, by improving their flexibility and agility, while maintaining their productivity and quality. Actually, the dynamic response to emergence is becoming a key issue, due to the weak response of the traditional manufacturing control systems to unexpected disturbances, mainly because of the rigidity of their control architectures. In these circumstances, the challenge is to develop manufacturing control systems with autonomy and intelligence capabilities, fast adaptation to the environment changes, more robustness against the occurrence of disturbances, and easier integration of manufacturing resources and legacy systems. Several architectures using emergent concepts and technologies have been proposed, in particular those based in the holonic manufacturing paradigm. Holonic manufacturing is a paradigm based in the ideas of the philosopher Arthur Koestler, who proposed the word holon to describe a basic unit of organisation in biological and social systems. A holon, as Koestler devised the term, is an identifiable part of a (manufacturing) system that has a unique identity, yet is made up of sub-ordinate parts and in turn is part of a larger whole. The introduction of the holonic manufacturing paradigm allows a new approach to the manufacturing problem, bringing the advantages of modularity, decentralisation, autonomy, scalability, and re-use of software components. This dissertation intends to develop an agile and adaptive manufacturing control architecture to face the current requirements imposed to the manufacturing enterprises. The architecture proposed in this dissertation addresses the need for the fast reaction to disturbances at the shop floor level, increasing the agility and flexibility of the enterprise, when it works in volatile environments, characterised by the frequent occurrence of unexpected disturbances. The proposed architecture, designated by ADACOR (ADAptive holonic COntrol aRchitecture for distributed manufacturing systems), is based in the holonic manufacturing paradigm, build upon autonomous and cooperative holons, allowing the development of manufacturing control applications that present all the features of decentralised and holonic systems. ADACOR holonic architecture introduces an adaptive control that balances dynamically between a more centralised structure and a more decentralised one, allowing to combine the global production optimisation with agile reaction to unexpected disturbances. Nas últimas décadas têm-se assistido a mudanças significativas no ambiente de fabrico: evoluindo de uma economia local para um economia global, com os mercados a procurar produtos com elevada qualidade a baixos preços, altamente customizados e com um ciclo de vida curto. Neste ambiente, as empresas de manufactura, para evitar o risco de perda de competitividade, procuram responder às solicitações dos clientes, melhorando a sua flexibilidade e agilidade, mantendo os mesmos índices de produtividade e qualidade. Na verdade, a resposta dinâmica à emergência está a tornar-se num assunto chave, devido `a fraca resposta a perturbações que os sistemas de controlo de fabrico tradicionais apresentam, principalmente devido à rigidez das suas arquitecturas de controlo. Nestas circunstâncias, é fundamental o desenvolvimento de sistemas de controlo de fabrico com capacidades de autonomia e inteligência, rápida adaptação às mudanças, maior robustez à ocorrência de perturbações e fácil integração de recursos físicos e sistemas legados. Diversas arquitecturas usando conceitos e tecnologias emergentes têm sido propostas, em particular algumas baseadas no paradigma da produção holónica. O paradigma da produção holónica é inspirado nas ideias de Arthur Koestler, que propôs a palavra holon para descrever uma unidade básica de organização de sistemas biológicos e sociais. Um holon, de acordo com a definição de Koestler, é uma parte identificável do sistema com identidade única, composta por sub-partes e fazendo simultaneamente parte do todo. A introdução do paradigma da produção holónica permite uma nova abordagem aos sistemas de controlo de fabrico, trazendo vantagens de modularidade, descentralização, autonomia, escalabilidade e reutilização de componentes. Esta dissertação pretende desenvolver uma arquitectura de controlo ágil e adaptativa que suporte os requisitos actuais impostos `as empresas de manufactura. A arquitectura proposta visa a necessidade de uma reacção rápida a perturbações, ao nível da planta fabril, melhorando a flexibilidade e agilidade da empresa quando esta opera em ambientes voláteis, caracterizados pela ocorrência frequente de perturbações inesperadas. A arquitectura proposta, designada por ADACOR (ADAptive holonic COntrol aRchitecture for distributed manufacturing systems), é baseada no paradigma da produção holónica e construída sobre holons autónomos e cooperativos, permitindo o desenvolvimento de aplicações de controlo de fabrico que apresentem todas as características dos sistemas descentralizados e holónicos. A arquitectura holónica ADACOR introduz um controlo adaptativo que balança dinamicamente entre uma estrutura de controlo mais centralizada e uma mais descentralizada, permitindo combinar a optimização da produção com a ágil reacção a perturbações.

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Reyes, Moro Antonio. "Scheduling of flexible manufacturing systems integrating Petri nets and artificial intelligence methods." Thesis, Liverpool John Moores University, 2000. http://researchonline.ljmu.ac.uk/5527/.

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The work undertaken in this thesis is about the integration of two well-known methodologies: Petri net (PN) model Ii ng/analysis of industrial production processes and Artificial Intelligence (AI) optimisation search techniques. The objective of this integration is to demonstrate its potential in solving a difficult and widely studied problem, the scheduling of Flexible Manufacturing Systems (FIVIS). This work builds on existing results that clearly show the convenience of PNs as a modelling tool for FIVIS. It addresses the problem of the integration of PN and Al based search methods. Whilst this is recognised as a potentially important approach to the scheduling of FIVIS there is a lack of any clear evidence that practical systems might be built. This thesis presents a novel scheduling methodology that takes forward the current state of the art in the area by: Firstly presenting a novel modelling procedure based on a new class of PN (cb-NETS) and a language to define the essential features of basic FIVIS, demonstrating that the inclusion of high level FIVIS constraints is straight forward. Secondly, we demonstrate that PN analysis is useful in reducing search complexity and presents two main results: a novel heuristic function based on PN analysis that is more efficient than existing methods and a novel reachability scheme that avoids futile exploration of candidate schedules. Thirdly a novel scheduling algorithm that overcomes the efficiency drawbacks of previous algorithms is presented. This algorithm satisfactorily overcomes the complexity issue while achieving very promising results in terms of optimality. Finally, this thesis presents a novel hybrid scheduler that demonstrates the convenience of the use of PN as a representation paradigm to support hybridisation between traditional OR methods, Al systematic search and stochastic optimisation algorithms. Initial results show that the approach is promising.

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Kim, Doosuk Mechanical &amp Manufacturing Engineering Faculty of Engineering UNSW. "Intelligent scheduling and control of automated guided vehicle considering machine loading in a flexible manufacturing system: using hopfield networks and simulation." Awarded by:University of New South Wales. School of Mechanical and Manufacturing Engineering, 2006. http://handle.unsw.edu.au/1959.4/29542.

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Flexible manufacturing systems (FMS) have received increasing attention from researchers and practitioners due to their potential advantages: quicker response to market changes, reduction in work-in-process (WIP), high inventory turnover and high levels of productivity. Two groups of problems in an FMS are of importance: (1) design problems and (2) operational problems. Operational problems can be effectively separated into 4 sub-problems: planning, grouping, machine loading problem (MLP) and scheduling. Problems from machine loading to scheduling and control of an FMS can be handled with neural networks approaches and simulation. The machine loading problem as a combinatorial optimization problem is actually a classic problem in operations research and is known to be NP-hard. MLP formulated as 0-1 integer programming problems has been solved by the methods of linearizing the nonlinear terms, branch and bound algorithm, and heuristic methods which have also been popularly applied. Hopfield Networks as a class of artificial neural networks have been adapted as an efficient method to solve the MLP, as these are able to find the solutions quickly through massive and parallel computation. Unfortunately, the quality of the solutions can occasionally be poor owing to the values of the weighting parameters in the energy function of the Hopfield Networks. One alternative approach used is to imbed mean field annealing into Hopfield Networks. The hybrid method of Hopfield Networks and mean field annealing can find near-optimal solutions as well as overcome the difficulties with decisions about the weighting of parameters in the energy function. The AGV scheduling problem can be regarded as the problem of selecting appropriate dispatch rules. Many dispatch rules have been introduced by a number of researchers. Even though vqarious formulations of the FMS scheduling problem can be presented, simulation methods are popular and often used. A solution methodology for MLP and AGV scheduling problems is proposed and specific models based on the literature are subjected to experimented through simulation. The proposed methodology can be also applied without difficulty to of breakdowns of machines and AGV. Results from simulation experiment s show that superior performance and capability of the proposed to existing methods are demonstrated by applying them to the test problems represented by simulation..

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Ghosal, Subhabrata. "Object Oriented Simulation of Agent Based Flexible Manufacturing System with Dynamic Routing and Scheduling." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1438812428.

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Touzani, Hicham. "Planification Multi-Robot du Problème de Répartition de Tâches avec Évitement Automatique de Collisions et Optimisation du Temps de Cycle : Application à la Chaîne de Production Automobile." Electronic Thesis or Diss., université Paris-Saclay, 2022. http://www.theses.fr/2022UPAST079.

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Dans l’industrie automobile, plusieurs robots sont nécessaires pour réaliser simultanément des séquences de soudage sur un même véhicule. L’attribution et la coordination des tâches de soudage entre les robots est une phase manuelle et exigeante qui doit être optimisée à l’aide d’outils automatiques. Le temps de cycle de la cellule dépend fortement de différents facteurs robotiques tels que la répartition des tâches entre les robots, les solutions de configuration et l’évitement d’obstacles. De plus, un aspect clé, souvent négligé dans l’état de l’art, est de définir une stratégie pour résoudre le séquencement des tâches robotiques avec une intégration efficace de l’évitement de collisions robot-robot. Cette thèse est motivée par la résolution de ce problème industriel et cherche à relever différents défis de recherche. Elle commence par présenter les solutions de pointe actuelles en matière de planification robotique. Une enquête approfondie est menée sur les solutions académiques/industrielles existantes pour résoudre le problème de répartition des tâches robotiques, en particulier pour les systèmes multi-robot. Cette enquête permet d’identifier les défis lors de l’intégration de plusieurs facteurs robotiques dans le processus d’optimisation. Cette thèse présente un algorithme itératif efficace qui génère une solution de haute qualité pour le problème de répartition de tâches multi-robot. Ce dernier gère non seulement les facteurs robotiques mentionnés, mais également les aspects liés aux contraintes d’accessibilité et à l’évitement de collisions mutuelles. De plus, un planificateur fait maison (RoboTSPlanner) gérant des robots à six axes a été validé dans un scénario de cas réel. Afin d’assurer l’exhaustivité de la méthodologie proposée, nous effectuons une optimisation dans l’espace des tâches, de configuration et de coordination de manière synergique. Par rapport aux approches existantes, la simulation comme les expérimentations réelles révèlent des résultats positifs en termes de temps de cycle et montrent la capacité de cette méthode à s’interfacer à la fois avec les logiciels de simulation industrielle et les outils ROS-I
In the automotive industry, several robots are required to simultaneously carry out welding sequences on the same vehicle. Assigning and coordinating welding tasks between robots is a manual and challenging phase that must be optimized using automatic tools. The cycle time of the cell strongly depends on different robotic factors such as the task allocation among the robots, the configuration solutions, and obstacle avoidance. Moreover, a key aspect, often neglected in the state-ofthe- art, is to define a strategy to solve the robotic task sequencing with an effective robot-robot collision avoidance integration. This thesis is motivated by solving this industrial problem and seeks to raise different research challenges. It begins by presenting the current state-of-the-art solutions regarding robotic planning. An in-depth investigation is carried out on the related existing academic/industrial solutions to solve the robotic task sequencing problem, particularly for multi-robot systems. This investigation helps identify the challenges when integrating several robotic factors into the optimization process. An efficient iterative algorithm that generates a high-quality solution for the Multi-Robotic Task Sequencing Problem is presented. This algorithm manages not only the mentioned robotic factors but also aspects related to accessibility constraints and mutual collision avoidance. In addition, a home-developed planner (RoboTSPlanner) handling six-axis robots has been validated in a real case scenario. In order to ensure the completeness of the proposed methodology, we perform optimization in the task, configuration, and coordination space in a synergistic way. Compared to the existing approaches, both simulation and real experiments reveal positive results in terms of cycle time and show the ability of this method to be interfaced with both industrial simulation software and ROS-I tools

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Demesure, Guillaume. "Coordination et planification de systèmes multi-agents dans un environnement manufacturier." Thesis, Valenciennes, 2016. http://www.theses.fr/2016VALE0029/document.

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Cette thèse porte sur la navigation d'agents dans un environnement manufacturier. Le cadre général du travail relève de la navigation d'AGVs (véhicules autoguidés), transportant librement et intelligemment leur produit. L'objectif est de proposer des outils permettant la navigation autonome et coopérative d’une flotte d’AGVs dans des systèmes de production manufacturiers où les contraintes temporelles sont importantes. Après la présentation d'un état de l'art sur chaque domaine (systèmes manufacturiers et navigation d'agents), les impacts de la mutualisation entre ceux-ci sont présentés. Ensuite, deux problématiques, liées à la navigation d'agents mobiles dans des environnements manufacturiers, sont étudiées. La première problématique est centrée sur la planification de trajectoire décentralisée où une fonction d'ordonnancement est combinée au planificateur pour chaque agent. Cette fonction permet de choisir une ressource lors de la navigation afin d'achever l'opération du produit transporté le plus tôt possible. La première solution consiste en une architecture hétérarchique où les AGVs doivent planifier (ou mettre à jour) leur trajectoire, ordonnancer leur produit pour l'opération en cours et résoudre leurs propres conflits avec les agents à portée de communication. Pour la seconde approche, une architecture hybride à l'aide d'un superviseur, permettant d'assister les agents durant leur navigation, est proposée. L'algorithme de planification de trajectoire se fait en deux étapes. La première étape utilise des informations globales fournies par le superviseur pour anticiper les collisions. La seconde étape, plus locale, utilise les données par rapport aux AGVs à portée de communication afin d'assurer l'évitement de collisions. Afin de réduire les temps de calcul des trajectoires, une optimisation par essaims particulaires est introduite. La seconde problématique se focalise sur la commande coopérative permettant un rendez-vous d'agents non holonomes à une configuration spécifique. Ce rendez-vous doit être atteint en un temps donné par un cahier des charges, fourni par le haut-niveau de contrôle. Pour résoudre ce problème de rendez-vous, nous proposons une loi de commande à temps fixe (i.e. indépendant des conditions initiales) par commutation permettant de faire converger l’état des AGVs vers une resource. Des résultats numériques et expérimentaux sont fournis afin de montrer la faisabilité des solutions proposées
This thesis is focused on agent navigation in a manufacturing environment. The proposed framework deals with the navigation of AGVs (Automated Guided Vehicles), which freely and smartly transport their product. The objective is to propose some tools allowing the autonomous and cooperative navigation of AGV fleets in manufacturing systems for which temporal constraints are important. After presenting the state of the art of each field (manufacturing systems and agent navigation), the impacts of the cross-fertilization between these two fields are presented. Then, two issues, related to the navigation of mobile agents in manufacturing systems, are studied. The first issue focuses on decentralized motion planning where a scheduling function is combined with the planner for each agent. This function allows choosing a resource during the navigation to complete the ongoing operation of the transported product at the soonest date. The first proposed approach consists in a heterarchical architecture where the AGVs have to plan (or update) their trajectory, schedule their product and solve their own conflict with communicating agents. For the second approach, hybrid architecture with a supervisor, which assists agents during the navigation, is proposed. The motion planning scheme is divided into two steps. The first step uses global information provided by the supervisor to anticipate the future collisions. The second step is local and uses information from communicating agents to ensure the collision avoidance. In order to reduce the computational times, a particle swarm optimization is introduced. The second issue is focused on the cooperative control, allowing a rendezvous of nonholomic agents at a specific configuration. This rendezvous must be achieved in a prescribed time, provided by the higher level of control. To solve this rendezvous, a fixed time (i.e. independent of initial conditions) switching control law is proposed, allowing the convergence of agent states towards a resource configuration. Some numerical and experimental results are provided to show the feasibility of the proposed methods

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Selke, Klaus Kurt Willi. "Intelligent assembly in flexible automation." Thesis, University of Hull, 1988. http://hydra.hull.ac.uk/resources/hull:8053.

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This work investigates the automation of assembly cells and the need to incorporate sensor-guided decision techniques. The experience of industry in this area is examined by observing a real cell on the shop floor. From the collected data conclusions point to an alternative error interpretation which describes the successful completion rather than an enumeration of errors. A methodology for the description of the process in robotic assembly is developed. The constituent phases in handling components are identified as Feeding, Transport and Mating. Each phase has well defined characteristic properties which can be determined using appropriate sensing mechanisms. The mating phase is given special attention by proposing the method of information Spaces as a suitable frame work for sensor fusion and context directed interpretation. Thus the successful progress is described regarding any deviations as errors. They in turn can be interpreted in the context in which they were encountered and recovery is accomplished in the demonstration cell by operator taught routines. Where error repetition occurs, a simple look-up technique suffices to remove the need for another operator intervention. The required data structures and the implementation of the experimental cell are discussed. It is concluded from the results that the principle of knowledge-based assembly control exhibits an intelligent behaviour which contributes to an increase in the cell productivity. This method addresses only a part of the overall problem of assembly automation, but it has a central place in the system and could be extended to the complete system.

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Aluskan, Aziz Batur. "Emulated Flexible Manufacturing Facility." [Florida] : State University System of Florida, 1999. http://etd.fcla.edu/etd/uf/1999/amj9902/aluskan.pdf.

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Thesis (M.S.)--University of Florida, 1999.
Title from first page of PDF file. Document formatted into pages; contains x, 90 p.; also contains graphics. Vita. Includes bibliographical references (p. 89).

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Chandrasekar, Subramanian. "The intelligent manufacturing workstation." Ohio : Ohio University, 1999. http://www.ohiolink.edu/etd/view.cgi?ohiou1175887566.

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Scott, Wesley Dane. "A flexible control system for flexible manufacturing systems." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/158.

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A flexible workcell controller has been developed using a three level control hierarchy (workcell, workstation, equipment). The cell controller is automatically generated from a model input by the user. The model consists of three sets of graphs. One set of graphs describes the process plans of the parts produced by the manufacturing system, one set describes movements into, out of and within workstations, and the third set describes movements of parts/transporters between workstations. The controller uses an event driven Petri net to maintain state information and to communicate with lower level controllers. The control logic is contained in an artificial neural network. The Petri net state information is used as the input to the neural net and messages that are Petri net events are output from the neural net. A genetic algorithm was used to search over alternative operation choices to find a "good" solution. The system was fully implemented and several test cases are described.

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Kanj, Matthieu. "Intelligent supervision of flexible optical networks." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S138/document.

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Les réseaux optiques dynamiques et flexibles font partie des scénarios d'évolution des réseaux de transport optique. Ceux-ci formeront la base de la nouvelle génération des réseaux optiques de demain et permettront le déploiement efficace des services tel que le Cloud Computing. Cette évolution est destinée à apporter flexibilité et automatisation à la couche optique, mais s'accompagne d'une complexité supplémentaire, notamment au niveau de la gestion et de la commande de cette toute nouvelle génération de réseau. Jusqu'à récemment, les protocoles de routage et de signalisation normalisés ont pris en compte plusieurs paramètres physiques tels que l'information spectrale de la bande passante, le format de modulation, et la régénération optique. Cependant, d'autres paramètres sont encore nécessaires (par exemple, les puissances optiques des liens, le gain des amplificateurs) afin de faire fonctionner efficacement de grands réseaux. Dans ce contexte, il y a un besoin d'étudier les réseaux optiques existants ainsi que les différentes méthodes de prise en compte de la couche photonique dans le plan de contrôle. Le but est d'avoir un réseau optique automatique, flexible et programmable, mais surtout efficace de point de vue économique et opérationnel. L'utilisation de la technologie à grille flexible a un impact sur les réseaux optiques existants, où presque tous les équipements devront être remplacés, ce qui entraînera un coût additionnel pour les opérateurs. Dans ce travail, nous étudions les réseaux optiques actuels et évaluons l'impact de la flexibilité sur les infrastructures existantes. Ensuite, nous identifions plusieurs paramètres optiques à contrôler et proposons des extensions protocolaires afin d'intégrer ces paramètres dans un plan de contrôle GMPLS. De plus, nous développons les algorithmes de routage et de signalisation qui permettent la mise en œuvre d'un plan de contrôle efficace qui répond au besoin de la flexibilité. Enfin, l'ensemble de nos propositions et de nos solutions sont évaluées sur plusieurs topologies réseaux avec des modèles de trafic différents dans le but de valider leur pertinence
Dynamic and flexible optical networks are among the evolution scenarios of the optical transport networks. These form the basis of the new generation of optical networks of tomorrow and enable the effective deployment of services such as cloud computing. This evolution is intended to provide flexibility and automation to the optical layer. However, it results in additional complexity, particularly in terms of the management and control of this new network generation. Until recently, the standardized routing and signaling protocols have been taking into account several optical parameters like the spectral bandwidth information, modulation format, and optical regeneration. However, other parameters (e.g., link optical powers, gain of optical amplifiers) are still required in order to efficiently operate large optical networks. In this context, there is a need to study the existing optical networks and the different integration methods of the photonic layer in a control plane. The goal is to get an automatic optical network that is flexible, programmable, and at the same time efficient from an economical and operational perspective. The use of flexible grid technology has an impact on existing optical networks, where almost all the equipment must be replaced, resulting in an additional cost to network operators. In this work, we study the current optical networks and evaluate the impact of flexibility on the existing infrastructures. Then, we identify several physical parameters to be controlled and propose protocol extensions in order to integrate these parameters in the GMPLS control plane. In addition, we develop the routing and signaling algorithms that allow the implementation of an efficient control plane that addresses the need for flexibility. Finally, the set of our proposals and solutions are evaluated on multiple network topologies with different traffic patterns in order to validate their relevance

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ONORI, RICCARDO. "Managing distributed flexible manufacturing systems." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2005. http://hdl.handle.net/2108/181.

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Per molti anni la ricerca scientifica si è concentrata sui diversi aspetti di gestione dei sistemi manifatturieri, dall’ottimizzazione dei singoli processi produttivi, fino alla gestione delle più complesse imprese virtuali. Tuttavia molti aspetti inerenti il coordinamento e il controllo, ancora presentano problematiche rilevanti in ambito industriale e temi di ricerca aperti. L’applicazione di tecnologie avanzate e di strumenti informatici evoluti non riesce da sola a garantire il successo nelle funzioni di controllo e di integrazione. Al fine di ottenere un alto grado di efficienza, è necessario supportare tali tecnologie e strumenti con dei modelli che siano in grado di rappresentare le funzionalità e i processi dei sistemi manifatturieri, e consentano di prevederne e gestirne l’evoluzione. Ne emerge l’esigenza di politiche di controllo e di gestio ne distribuite, che favoriscano l’auto-organizzazione e la cooperazione nei sistemi manifatturieri. I sistemi manifatturieri flessibili distribuiti (DFMS), in risposta a tale esigenza, sono sistemi di produzione dinamici in grado di garantire una risposta in tempo reale alla allocazione ottima delle risorse, e organizzare efficientemente le lavorazioni dei prodotti. In questa tesi viene proposta una modellizzazione a livelli per tali sistemi. Secondo tale rappresentazione un DFMS può essere visto come un grafo strutturato su più livelli, tale che: i vertici del grafo rappresentano le risorse interagenti nel sistema; ogni nodo di un livello rappresenta a sua volta un livello successivo. Partendo da questa rappresentazione, sono stati quindi sviluppati due modelli per lo studio dell’allocazione ottima delle risorse (task mapping) e per l’organizzazione di lavorazioni (task scheduling) che richiedono l’uso simultaneo di risorse condivise nel sistema. Il task mapping problem consiste nella suddivisione bilanciata di un certo insieme di lavorazioni tra le risorse del sistema. In questa tesi si è studiato il caso in cui le lavorazioni sono omogenee, non presentano vincoli di precedenza, ma necessitano di un certo volume di comunicazione tra le risorse cui sono assegnate per garantirne il coordinamento, incidendo in tal senso sulla complessità di gestione. L’analisi critica dei modelli che sono tipicamente usati in letteratura per rappresentare tale problema, ne hanno posto in evidenza l’inadeguatezza. Attraverso alcuni risultati teorici si è quindi dimostrato come il problema possa ricondursi ad un hypergraph partitioning problem. Studiando la formulazione matematica di tali problemi, e limitandosi al caso di due risorse produttive, si è infine giunti alla determinazione di una buona approssimazione sulla soluzione ottima. Il problema di sequenziamento delle lavorazioni (task scheduling) che richiedono l’uso simultaneo di risorse condivise è stato trattato nel caso specifico di celle robotizzate. E’ stata quindi dimostrata l’NP-completezza di questo problema ed è stata progettata una euristica di soluzione, validandone i risultati in diversi scenari produttivi.
For several years, research has focused on several aspects of manufacturing, from the individual processes towards the management of virtual enterprises, but several aspects, like coordination and control, still have relevant problems in industry and remain challenging areas of research. The application of advanced technologies and informational tools by itself does not guarantee the success of control and integration applications. In order to get a high degree of integration and efficiency, it is necessary to match the technologies and tools with models that describe the existing knowledge and functionality in the system and allow the correct understanding of its behaviour. In a global and wide market competition, the manufacturing systems present requirements that lead to distributed, self-organised, co-operative and heterogeneous control applications. A Distributed Flexible Manufacturing System (DFMS) is a goal-driven and data-directed dynamic system which is designed to provide an effective operation sequence for the products to fulfil the production goals, to meet real-time requirements and to optimally allocate resources. In this work first a layered approach for modeling such production systems is proposed. According to that representation, a DFMS may be seen as multi-layer resource-graph such that: vertices on a layer represent interacting resources; a layer at level l is represented by a node in the layer at level (l-1). Then two models are developed concerning with two relevant managerial issues in DFMS, the task mapping problem and the task scheduling with multiple shared resources problem. The task mapping problem concerns with the balanced partition of a given set of jobs and the assignment of the parts to the resources of the manufacturing system. We study the case in which the jobs are quite homogeneous, do not have precedence constraints, but need some communications to be coordinated. So, jobs assignment to different parts causes a relevant communication effort between those parts, increasing the managerial complexity. We show that the standard models usually used to formal represent such a problem are wrong. Through some graph theoretical results we relate the problem to the well-known hypergraph partitioning problem and briefly survey the best techniques to solve the problem. A new formulation of the problem is then presented. Some considerations on an improved version of the formulation permit the computation of a good Lower Bound on the optimal solution in the case of the hypergraph bisection. The task scheduling with multiple shared resources problem is addressed for a robotic cell. We study the general problem of sequencing multiple jobs, where each job consists of multiple ordered tasks and tasks execution requires simultaneous usage of several resources. NP-completeness results are given. A heuristic with a guarantee approximation result is designed and evaluated.

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Quinn, Liam. "Intelligent design of manufacturing systems." Thesis, De Montfort University, 1996. http://hdl.handle.net/2086/10696.

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The design of a manufacturing system is normally performed in two distinct stages, i.e. steady state design and dynamic state design. Within each system design stage a variety of decisions need to be made of which essential ones are the determination of the product range to be manufactured, the layout of equipment on the shopfloor, allocation of work tasks to workstations, planning of aggregate capacity requirements and determining the lot sizes to be processed. This research work has examined the individual problem areas listed above in order to identify the efficiency of current solution techniques and to determine the problems experienced with their use. It has been identified that for each design problem. although there are an assortment of solution techniques available, the majority of these techniques are unable to generate optimal or near optimal solutions to problems of a practical size. In addition, a variety of limitations have been identified that restrict the use of existing techniques. For example, existing methods are limited with respect to the external conditions over which they are applicable and/or cannot enable qualitative or subjective judgements of experienced personnel to influence solution outcomes. An investigation of optimization techniques has been carried out which indicated that genetic algorithms offer great potential in solving the variety of problem areas involved in manufacturing systems design. This research has, therefore, concentrated on testing the use of genetic algorithms to make individual manufacturing design decisions. In particular, the ability of genetic algorithms to generate better solutions than existing techniques has been examined and their ability to overcome the range of limitations that exist with current solution techniques. IIFor each problem area, a typical solution has been coded in terms of a genetic algorithm structure, a suitable objective function constructed and experiments performed to identify the most suitable operators and operator parameter values to use. The best solution generated using these parameters has then been compared with the solution derived using a traditional solution technique. In addition, from the range of experiments undertaken the underlying relationships have been identified between problem characteristics and optimality of operator types and parameter values. The results of the research have identified that genetic algorithms could provide an improved solution technique for all manufacturing design decision areas investigated. In most areas genetic algorithms identified lower cost solutions and overcame many of the limitations of existing techniques.

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Gasmi, Bernadette. "Safir : système d'assemblage flexible intelligent multi-robots." Toulouse, ENSAE, 1990. http://www.theses.fr/1990ESAE0014.

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Ce mémoire de thèse présente un environnement de programmation pour une cellule flexible d'assemblage multi-robots: SAFIR. Il comprend un mode hors-ligne qui correspond à l'interface opérateur (spécification des graphes d'assemblage contenant plusieurs plans d'assemblage d'un même produit; instanciation des bases de données concernant les pièces à assembler et les liaisons existant entre elles) et un mode en-ligne qui gère et supervise l'exécution des tâches d'assemblage de manière dynamique. L'objectif est de s'adapter, en temps réel, à l'évolution de la cellule (retard de pièces, pannes de ressources,. . . ). SAFIR utilise une approche distribuée des connaissances sur les pièces, les ressources, les tâches d'assemblage, etc. . . Son implémentation s'appuie sur les concepts de programmation orientée objet (encapsulation et niveau d'abstraction des données).

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Mather, Charles. "Flexible manufacturing in Vancouver's clothing industry." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28112.

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Flexible production techniques have been implemented in a number of industries in response to the crisis following the long post World War Two boom. These new methods have recently captured the attention of social scientists from a broad range of perspectives. In the large North American automobile industry, where flexible manufacturing is best documented, firms are introducing programmable equipment, work teams are replacing the assembly line, inventories are kept at a minimum, improving turnaround time and quality are important goals, and markets are smaller as specific consumers are targeted. However, it is becoming increasingly clear that the experience of the automobile industry is not representative of other manufacturing sectors. The implementation of the new techniques is likely to be different where the organisation of production is different, the structure of the industry is less concentrated, and where norms of consumption are distinct. This thesis focuses on the clothing industry in Vancouver, British Columbia. For this study, interviews were conducted with fourteen clothing firms in the city, ten workers (most of whom were Chinese female immigrants), union officials, equipment salespeople and a government official. The primary research question was to understand the pervasiveness of the new techniques and their effects on workers and the industry in Vancouver. The results of this study suggest that it is overwhelmingly the very large fashion firms that have invested in flexible machinery. These firms are large enough to lay out the capital for the new machines which improve turnaround time and flexibility, both vital for manufacturers of fashion apparel. A second advantage of the equipment for factory owners is that it reduces their dependence on skilled male workers who command the highest wages on the shop floor. For women workers in the industry (machinists), the new machines simply speed up work, making an already debilitating job worse. On the other hand, many smaller fashion firms are unable to raise the capital for the equipment even though the potential benefits are significant. In addition, standardised clothing manufacturers in Vancouver have not purchased the new technology because it does not suit their needs. Firms without the new technology weather downturns in the economy primarily through workers in the secondary labour market, which, in Vancouver is dominated by immigrant women. At this stage it seems that are barriers to the widespread implementation of flexible equipment in Vancouver clothing industry.
Arts, Faculty of
Geography, Department of
Graduate

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Desai, Neha K. "Scheduling algorithm for flexible manufacturing cells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23274.pdf.

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Washington, Lisa Anne. "Effectiveness analysis of flexible manufacturing systems." Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/15317.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1985.
MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.
Bibliography: leaves 112-114.
by Lisa Anne Washington.
M.S.

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Dadone, Paolo. "Fuzzy Control of Flexible Manufacturing Systems." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/36531.

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Flexible manufacturing systems (FMS) are production systems consisting of identical multipurpose numerically controlled machines (workstations), automated material handling system, tools, load and unload stations, inspection stations, storage areas and a hierarchical control system. The latter has the task of coordinating and integrating all the components of the whole system for automatic operations. A particular characteristic of FMSs is their complexity along with the difficulties in building analytical models that capture the system in all its important aspects. Thus optimal control strategies, or at least good ones, are hard to find and the full potential of manufacturing systems is not completely exploited.

The complexity of these systems induces a division of the control approaches based on the time frame they are referred to: long, medium and short term. This thesis addresses the short-term control of a FMS. The objective is to define control strategies, based on system state feedback, that fully exploit the flexibility built into those systems. Difficulties arise since the metrics that have to be minimized are often conflicting and some kind of trade-offs must be made using "common sense". The problem constraints are often expressed in a rigid and "crisp" way while their nature is more "fuzzy" and the search for an analytical optimum does not always reflect production needs. Indeed, practical and production oriented approaches are more geared toward a good and robust solution.

This thesis addresses the above mentioned problems proposing a fuzzy scheduler and a reinforcement-learning approach to tune its parameters. The learning procedure is based on evolutionary programming techniques and uses a performance index that contains the degree of satisfaction of multiple and possibly conflicting objectives. This approach addresses the design of the controller by means of language directives coming from the management, thus not requiring any particular interface between management and designers.

The performances of the fuzzy scheduler are then compared to those of commonly used heuristic rules. The results show some improvement offered by fuzzy techniques in scheduling that, along with ease of design, make their applicability promising. Moreover, fuzzy techniques are effective in reducing system congestion as is also shown by slower performance degradation than heuristics for decreasing inter- arrival time of orders. Finally, the proposed paradigm could be extended for on-line adaptation of the scheduler, thus fully responding to the flexibility needs of FMSs.

Master of Science

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Lee, Bill W. J. "The cost conflicts of flexible manufacturing." Thesis, University of Bath, 1993. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306834.

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Scott, Peter. "Craft skills in flexible manufacturing systems." Thesis, University of Bath, 1987. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377776.

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Gelgele, Hirpa Lemu. "Hybrid Intelligent Systems in Manufacturing Optimization." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-45.

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The main objective of the work reported in this thesis has been to study and develop methodologies that can improve the communication gap between design and manufacturing systems. The emphasis has been on searching for the possible means of modeling and optimizing processes in an integrated design and manufacturing system environment using the combined capabilities (hybrids) of computational intelligence tools particularly that of artificial neural networks and genetic algorithms.

Within the last two decades, a trend of interest towards use of computers has been observed in almost all business activities. This has forced the industrial business to undergo dynamic profound changes with automation through information and communication technology being on the forefront of business success. Business in manufacturing engineering is no exceptional to this trend. Several functions in the manufacturing field such as design, process planning and manufacturing have enjoyed the recent advances in information and communication technology. However, the earlier isolated automation in each function have created a significant hindrance to smooth flow of information particularly because there has been a very high system incompatibility among the computerized systems.

One of the most difficult problems in modern manufacturing is the instability of production systems to mimic the basis human capabilities such as adjusting appropriately to the ever-changing environment. From past studies, it has been possible to witness that advances in theory and application methodology of artificial intelligence techniques can overcome many of the obstacles existing in manufacturing discipline. Today, the emergence of advanced computational methods in the artificial intelligence world such as genetic algorithms and neural networks, both inspired by the natural evolutionary process, has created a new field of research and application referred to as computational intelligence (CI) approach.

Accordingly, this thesis focuses on the application of computational intelligence tools from two main perspectives. On the one hand, instead of the isolated automation of each manufacturing function, the CI techniques have been considered as powerful tools that allow all functions to operate within a fully integrated and intelligent manufacturing system. Particularly, since process planning, is the main linking element between design and manufacturing functions, an automated and optimized process planning function creates a much more powerful environment that leads to the optimization of the whole process. Particularly, being able to integrate feature recognition and operation sequence optimization is an important element in the manufacturing system chain that can highly contribute to the automation and flexibility of the integrated design and manufacturing system. On the other hand, the computational intelligence techniques themselves have certain weakness of their own in solving the complex manufacturing process as a stand-alone form. In a hybrid form, however, they can either support or complement each other.

To realize these two points, this thesis has focused on the development of theories and application methodologies of hybrid computational intelligence systems to model and optimize complex manufacturing processes. The aim is to exploit the strong side of one computational intelligence tool and support or complement the weakness of the other. To this effect, qualitative analysis and reasoning of computational intelligence based hybrid systems are comprehensively discussed. The development theoretical backgrounds and methodologies are further used in key problem areas of the manufacturing system such as operation sequencing, machining economics analysis using multi-objective optimization approach and modeling and optimization of unstructured data collected from a non-conventional machining environment (electro-discharge machining). The results from the hybrid CI application to model and optimize the electro-discharge machine show that the methodology is also important not only to the industrial activities using this technology, but also promotes further research and application in the discipline. Though the focus in this thesis has been on discrete part manufacturing industries, it is important to mention that the facts, the developed methodologies and the discussed issues in the study are applicable to other industrial businesses.

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Salzman, Rhonda A. (Rhonda Ann) 1978. "Manufacturing system design : flexible manufacturing systems and value stream mapping." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/82697.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references.
by Rhonda A. Salzman.
S.M.

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Zain, Mohd Zarhamdy Md. "Modelling and intelligent control of flexible-link manipulators." Thesis, University of Sheffield, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425486.

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Schlechter, E. J. (Emile Johan). "Manufacturing intelligence : a dissemination of intelligent manufacturing principles with specific application." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52927.

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Thesis (MEng)--University of Stellenbosch, 2002.
ENGLISH ABSTRACT: Artificial intelligence has provided several techniques with applications in manufacturing. Knowledge based systems, neural networks, case based reasoning, genetic algorithms and fuzzy logic have been successfully employed in manufacturing. This thesis will provide the reader with an introduction and an understanding of each of these techniques (Chapter 2 & 3). The intelligent manufacturing process can be a complex one and can be decomposed into several components: intelligent design, intelligent process planning, intelligent quality management, intelligent maintenance and diagnosis, intelligent scheduling and intelligent control. This thesis will focus on how each of the artificial intelligence techniques can be applied to each of the manufacturing process fields. Chapter 5 Chapter 6 Chapter 7 Knowledge based systems Neural networks Fuzzy logic Case based reasoning Genetic algorithms Chapter 8 Chapter 9 Chapter 10 Manufacturing intelligence can be approached from two main directions: theoretical research and practical application. Most of the concepts, methods and techniques discussed in this thesis are approached from a theoretical research point of view. This thesis is also aimed at providing the reader with a broader picture of manufacturing intelligence and how to apply the intelligent techniques, in theory. Specific attention will be given to intelligent scheduling as an application (Chapter 11). The application will demonstrate how case based reasoning can be applied in intelligent scheduling within a small manufacturing plant.
AFRIKAANSE OPSOMMING: Kunsmatige intelligensie bied 'n verskeidenheid tegnieke en toepassings in die vervaardigingsomgewing. Kennis baseerde sisteme, neurale netwerke, gevalle basseerde redenasie, generiese algoritmes en wasige logika word suksesvol in die vervaardigingsopset toegepas. Dié tesis gee die leser 'n inleiding en basiese oorsig van metodes om elk van die tegnieke te gebruik (hoofstuk 2 & 3). Die intelligente vervaardigingproses is 'n komplekse proses en kan afgebreek word in verskeie komponente: intelligente ontwerp, intelligente prosesbeplanning, intelligente gehaltebestuur, intelligente onderhoud en diagnose, intelligente kontrole en intelligente skedulering. Hierdie tesis sal fokus op hoe elk van die kunsmatige intelligente tegnieke op elk van die vervaardigingprosesvelde toegepas kan word. Hoofstuk 5 Hoofstuk 6 Hoofstuk 7 Kennis gebaseerde sisteme Wasige logika Neurale netwerke Gevalle baseerde redenasie Generiese algoritmes Hoofstuk 8 Hoofstuk 9 Hoofstuk 10 Vervaardigingsintelligensie kan vanuit twee oogpunte benader word, naamlik 'n teoretiese ondersoek en 'n praktiese aanslag. Die meeste van hierdie konsepte, metodes en tegnieke word in hierdie tesis vanuit 'n teoretiese oogpunt benader. Die tesis is daarop gerig om die leser 'n wyer perspektief te gee van intelligente vervaardiging en hoe om die intelligente tegnieke, in teorie, toe te pas. Spesifieke aandag sal gegee word aan intelligente skedulering as 'n toepassing (Hookstuk 11). Die toepassing sal demonstreer hoe gevalle baseerde redenasie toegepas kan word in intelligente skedulering.

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Lap-Keung, Chu. "Design and operation of flexible manufacturing cells." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.276498.

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丘杰 and Jie Qiu. "Scheduling flexible manufacturing systems using fuzzy heuristics." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31244671.

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Ng, Koon-hung, and 吳冠雄. "Dynamic process planning for flexible manufacturing cells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31240823.

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Wybrow, M. "An ultrasonic recognition system for flexible manufacturing." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381070.

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Farshbaf, Mohamad Reza. "Mixed metal forming/machining flexible manufacturing system." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277924.

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Doulgeri, Z. "Production scheduling policy for flexible manufacturing systems." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38292.

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Altobelli, Frank Robert. "Flexible manufacturing systems and the housing industry." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43352.

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Granados, Fernández Víctor Hugo. "Modelling and optimization of flexible manufacturing systems." Master's thesis, Instituto Politécnico de Bragança, Escola Superior de Tecnologia e Gestão, 2012. http://hdl.handle.net/10198/7982.

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The Lagrangian relaxation method for solving a Mixed-Integer Linear Problem was implemented in order to improve the current TEMPO-PSI team exible manufacturing system solutions, available at the AIP-primeca pole in University of Valenciennes, France. The MILP optimization model, from TEMPO-PSI team, can not guarantee good results when the amount of jobs in the manufacturing system increases due to the growth in the number of variables of the model. A study on the optimization model was conducted with the objective to nd the candidate constraints for Lagrangian relaxation. A comparative study is made between the initial model solutions and Lagrange-relaxed model solutions. The results of the present research indicate that the use of the Lagrangian relaxation method on the scheduling problems could have advantages in obtaining better solutions. Um método relaxação lagrangeana para resolver um problema de Programação Misto- Inteira Linear foi implementado com o objetivo de melhorar as soluções actuais dos sistemas de manufatura exíveis da equipa TEMPO-PSI, disponível no laboratório AIPprimeca da Universidade de Valenciennes, França. O modelo de optimização MILP, da equipa TEMPO-PSI, não consegue garantir bons resultados quando a quantidade de operações no sistema de manufactura aumenta, devido ao crescimento do número de variáveis do modelo. O estudo do modelo de optimização foi levado a cabo com o objectivo de encontrar as restrições candidatas para a relaxação Lagrangeana. O estudo comparativo é feito entre as soluções iniciais do modelo e as soluções do modelo relaxado com o método de Lagrange. Os resultados da presente investigação indicam que o uso de método da relaxação Lagrangeana nos problemas de escalonamento de tarefas poderá ter vantagens na obtenção de melhores soluções.

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Whitehead, Jonathan David. "Scheduling and layout in flexible manufacturing systems." Thesis, University of Southampton, 2002. https://eprints.soton.ac.uk/50617/.

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This thesis covers a variety of inter-related scheduling and layout issues encountered in flexible manufacturing systems. The principal focus is upon systems which adopt the commonly implemented loop layout configuration. A pivotal idea behind the work is that products must revisit machines during their manufacture. The work encompasses both computational and theoretical results. The computational work consists of testing both new and standard heuristic and local search techniques on two strongly NP-hard combinatorial optimisation problems, one related to layout and the other to single machine scheduling. In the layout problem, machines must be sequenced around a loop of conveyor belt with the objective of minimising the amount of movement carried out by the worst affected product type within the manufacturing system. In the single machine scheduling problem, coupledoperation jobs must be scheduled so that the maximum completion time on the machine, the makespan, is minimised; each coupled-operation job consists of two arbitrary processing time operations separated by a time lag that is bounded both below and above. Our results suggest that local search techniques, while well suited to standard search spaces, do not perform well when the search space contains infeasible neighbours and the cost of evaluating candidate solutions is high. The theoretical work stems from the repetitive manufacture of single product types in loop layout flexible manufacturing systems. We demonstrate that in such a system, the efficiency is strongly governed by the balance of workloads on the machines. We develop mixed integer programming models for tool allocation and machine sequencing with the objective of balancing workloads, and as a secondary criterion, minimising product movement. Focusing on a single machine, we study the computational complexity of a class of coupled-operation scheduling problems; each job consists of two unit processing time operations separated by a fixed delay of two units of time, and their order of production is restricted by precedence constraints. For several standard scheduling objective functions, we provide either polynomial algorithms or proof of NP-hardness for parallel chain and tree precedence constraints.

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Dhooky, Aruna N. D. "Development of a flexible manufacturing system (FMS)." Master's thesis, University of Cape Town, 2004. http://hdl.handle.net/11427/5572.

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Includes bibliographical references.
This report describes how the latest technology in computing and interfacing has been used in a traditional manufacturing environment to integrate old stand-alone CNC machines, a FANUC robot, a conveyor and a Robot Positioning Device (RPD) into a Flexible Manufacturing System (FMS). Also described are the benefits that South African manufacturers still using old CNC machines could achieve if they implemented a similar process in their organisation.

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Martin, Timothy Patrick. "Flexible manufacturing system software development using simulation." Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/101236.

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This paper presents a hierarchical modeling method that can be used to simulate a Flexible Manufacturing System (FMS) at all levels of detail. The method was developed specifically to aid the software development needed for the hierarchy of computers that are present in an FMS. The method was developed by modeling an existing FMS. The models developed of the existing FMS are described in detail to provide an example of how to model other FMSs. The basic building blocks needed for designing other FMSs with this modeling method are provided. The models were written in the SIMAN simulation language. SIMAN was found to be an easy language to use for the hierarchical modeling of FMSs.
M.S.

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Ng, Koon-hung. "Dynamic process planning for flexible manufacturing cells /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22029709.

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Chen, Yufeng. "Optimal supervisory control of flexible manufacturing systems." Thesis, Paris, CNAM, 2015. http://www.theses.fr/2015CNAM0990/document.

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Notre thèse est consacrée à l’étude de la supervision des réseaux de Petri en vue de la conception de systèmes manufacturiers flexibles. L’objectif est la définition de stratégies de pilotage en ligne pour l’évitement de conflits et d’interblocages, dans le cadre de la théorie de la supervision. Le point de départ de notre travail est d’exploiterle graphe de marquage du réseau de Petri, ce qui permet en particulier d’obtenir des stratégies de commande maximalement permissive pour des problèmes d’évitement de conflits et d’interblocages. Nous avons ainsi introduit des techniques originales, manipulations d’inégalités ou réductions d’ensembles de marquages, destinées à diminuerla complexité algorithmique d’une telle méthode. Dans premier temps, nous avons focalisé sur la synthèse de superviseurs dits purs, ce qui correspond au cas particulier où l’ensemble de marquage légaux, est convexe.Cette optimisation est ensuite considérée du point de vue de la facilité de mise en oeuvre. Nous traitons ainsi de la minimisation de la structure du superviseur et de son coût d’implémentation en préservant une structure de supervision qui offre à la fois la permissivité maximale et une complexité de calcul raisonnable en vue d’utilisationsur des installations réelles. Aussi, nous avons cherché à réduire le nombre de places de contrôle nécessaires pour réaliser un superviseur maximalement permissif, pour cela nous avons formule le calcul du nombre minimal de places de contrôle en termes d’un problème de programmation linéaire. Afin d’affaiblir la complexité de ce calcul de superviseur, deux versions de l’algorithme sont proposées. Ce problème de minimisation de la taille dusuperviseur, quoique fondamental, n’est pas abordé aussi directement dans la littérature. Il s’agit là d’une première contribution.Dans u second temps, nous nous sommes intéressés aux réseaux de Petri à boucles (self-loops). Les boucles étant représentées par une variable qui s’ajoute dans la contrainte inégalité définissant l’ensemble de marquages légaux. Après avoir proposé une méthode de réduction du nombre d’inégalités ainsi que du superviseur optimalen se basant sur les approches et résultats précédents, nous avons établi une condition suffisante d’obtention d’un superviseur maximalement permissif permettant de traiter des ensembles de marquages légaux non convexes.Enfin nous proposons une méthode de synthèse de contrôleur pour une nouvelle classe de réseaux de Petri, avec des arcs inhibiteurs correspondant à des contraintes définies par des intervalles. La taille du contrôleur ainsi obtenu et défini en termes d’arcs inhibiteurs à intervalles s’en trouve réduite ainsi que par conséquent sont coût d’implémentation
Reachability graph analysis is an important technique for deadlockcontrol, which always suffers from a state explosion problem since it requires togenerate all or a part of reachable markings.Based on this technique, an optimal or suboptimal supervisor with high behavioralpermissiveness can always be achieved. This thesis focuses on designing liveness enforcing Petri net supervisors for FMSs by considering their behavioralpermissiveness, supervisory structure, and computationnal complexity.The following research contributions are made in this thesis.1. The design of a maximally permissive liveness-enforcing supervisor for an FMSis proposed by solving integer linear programming problems (ILPPs).2. Structural complexity is also an important issue for a maximally permissivePetri net supervisor. A deadlock prevention policy for FMSs is proposed, which canobtain a maximally permissive liveness-enforcing Petri net supervisor while thenumber of control places is compressed.3. In order to overcome the computational complexity problem in MCPP and ensurethat the controlled system is maximally permissive with a simple structure, wedevelop an iterative deadlock prevention policy and a modified version.4. We consider the hardware and software costs in the stage of controlimplementation of a deadlock prevention policy, aiming to obtain a maximallypermissive Petri net supervisor with the lowest implementation cost. A supervisorconsists of a set of control places and the arcs connecting control places totransitions. We assign an implementation cost for each control place and controland observation costs for each transition. Based on reachability graph analysis,maximal permissiveness can be achieved by designing place invariants that prohibitall FBMs but no legal markings.5. Self-loops are used to design maximally permissive supervisors. A self-loop ina Petri net cannot be mathematically represented by its incidence matrix. Wepresent a mathematical method to design a maximally permissive Petri netsupervisor that is expressed by a set of control places with self-loops. A controlplace with a self-loop can be represented by a constraint and a selfloopassociated with a transition whose firing may lead to an illegal marking

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Chen, Yufeng. "Optimal supervisory control of flexible manufacturing systems." Electronic Thesis or Diss., Paris, CNAM, 2015. http://www.theses.fr/2015CNAM0990.

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Notre thèse est consacrée à l’étude de la supervision des réseaux de Petri en vue de la conception de systèmes manufacturiers flexibles. L’objectif est la définition de stratégies de pilotage en ligne pour l’évitement de conflits et d’interblocages, dans le cadre de la théorie de la supervision. Le point de départ de notre travail est d’exploiterle graphe de marquage du réseau de Petri, ce qui permet en particulier d’obtenir des stratégies de commande maximalement permissive pour des problèmes d’évitement de conflits et d’interblocages. Nous avons ainsi introduit des techniques originales, manipulations d’inégalités ou réductions d’ensembles de marquages, destinées à diminuerla complexité algorithmique d’une telle méthode. Dans premier temps, nous avons focalisé sur la synthèse de superviseurs dits purs, ce qui correspond au cas particulier où l’ensemble de marquage légaux, est convexe.Cette optimisation est ensuite considérée du point de vue de la facilité de mise en oeuvre. Nous traitons ainsi de la minimisation de la structure du superviseur et de son coût d’implémentation en préservant une structure de supervision qui offre à la fois la permissivité maximale et une complexité de calcul raisonnable en vue d’utilisationsur des installations réelles. Aussi, nous avons cherché à réduire le nombre de places de contrôle nécessaires pour réaliser un superviseur maximalement permissif, pour cela nous avons formule le calcul du nombre minimal de places de contrôle en termes d’un problème de programmation linéaire. Afin d’affaiblir la complexité de ce calcul de superviseur, deux versions de l’algorithme sont proposées. Ce problème de minimisation de la taille dusuperviseur, quoique fondamental, n’est pas abordé aussi directement dans la littérature. Il s’agit là d’une première contribution.Dans u second temps, nous nous sommes intéressés aux réseaux de Petri à boucles (self-loops). Les boucles étant représentées par une variable qui s’ajoute dans la contrainte inégalité définissant l’ensemble de marquages légaux. Après avoir proposé une méthode de réduction du nombre d’inégalités ainsi que du superviseur optimalen se basant sur les approches et résultats précédents, nous avons établi une condition suffisante d’obtention d’un superviseur maximalement permissif permettant de traiter des ensembles de marquages légaux non convexes.Enfin nous proposons une méthode de synthèse de contrôleur pour une nouvelle classe de réseaux de Petri, avec des arcs inhibiteurs correspondant à des contraintes définies par des intervalles. La taille du contrôleur ainsi obtenu et défini en termes d’arcs inhibiteurs à intervalles s’en trouve réduite ainsi que par conséquent sont coût d’implémentation
Reachability graph analysis is an important technique for deadlockcontrol, which always suffers from a state explosion problem since it requires togenerate all or a part of reachable markings.Based on this technique, an optimal or suboptimal supervisor with high behavioralpermissiveness can always be achieved. This thesis focuses on designing liveness enforcing Petri net supervisors for FMSs by considering their behavioralpermissiveness, supervisory structure, and computationnal complexity.The following research contributions are made in this thesis.1. The design of a maximally permissive liveness-enforcing supervisor for an FMSis proposed by solving integer linear programming problems (ILPPs).2. Structural complexity is also an important issue for a maximally permissivePetri net supervisor. A deadlock prevention policy for FMSs is proposed, which canobtain a maximally permissive liveness-enforcing Petri net supervisor while thenumber of control places is compressed.3. In order to overcome the computational complexity problem in MCPP and ensurethat the controlled system is maximally permissive with a simple structure, wedevelop an iterative deadlock prevention policy and a modified version.4. We consider the hardware and software costs in the stage of controlimplementation of a deadlock prevention policy, aiming to obtain a maximallypermissive Petri net supervisor with the lowest implementation cost. A supervisorconsists of a set of control places and the arcs connecting control places totransitions. We assign an implementation cost for each control place and controland observation costs for each transition. Based on reachability graph analysis,maximal permissiveness can be achieved by designing place invariants that prohibitall FBMs but no legal markings.5. Self-loops are used to design maximally permissive supervisors. A self-loop ina Petri net cannot be mathematically represented by its incidence matrix. Wepresent a mathematical method to design a maximally permissive Petri netsupervisor that is expressed by a set of control places with self-loops. A controlplace with a self-loop can be represented by a constraint and a selfloopassociated with a transition whose firing may lead to an illegal marking

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Gupta, Avaneesh. "Characterization and measurement of manufacturing flexibility for production planning in high mix low volume manufacturing system /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?IEEM%202004%20GUPTA.

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Fleischman, David R. "A data oriented approach to integrating manufacturing functions in flexible Manufacturing Systems." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/23150.

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Computer Integrated Manufacturing (CIM) seeks to integrate computers into the manufacturing environment, with the end result being a more efficient and productive factory. Current approaches to CIM generally fail to truly integrate the various manufacturing functions (design, scheduling, planning, manufacture, business, etc.) and instead result in self-sufficient, computer- served 'islands of automation.' In these systems, data must be translated before moving from one manufacturing function to another. Wu and Madison have approached data modeling in a CIM environment from a new perspective. Their approach seeks to provide one data model that meets the needs of all manufacturing functions within a factory, negating the need for human or machine data translators. Keywords: Computer integrated manufacturing; Flexible manufacturing systems; Data modeling

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Fan, Tao. "Intelligent model predictive control of flexible link robotic manipulators." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31300.

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This thesis develops and evaluates an intelligent model predictive control (IMPC) strategy for motion control of a flexible link robotic manipulator through analysis, computer simulation, and physical experimentation. The developed IMPC is based on a two-level hierarchical control architecture. This control structure is used to combine the advantages of the conventional model predictive control (MPC) with those of knowledge-based soft control techniques. The upper level of the structure is a fuzzy-rule based intelligent decision-making system. The lower level consists of two modules: a real-time system identification module (which adjusts the model parameters and accommodates payload changes of the manipulator), and a model predictive control (MPC) module (which develops control inputs based on the linear model generated by the system identification module). The upper-level intelligent fuzzy rule-based tuner interacts with the lower level modules. Based on the desired system performance, the state feedback signals, and the knowledge base, the upper-level fuzzy tuner automatically adjusts the tuning parameters of the MPC controller. It is also able to adjust the model structure of the system-identification module, if necessary, to accommodate large model errors, and will increase the robustness of the controller. An explicit, complete, and accurate nonlinear dynamic model of the system is developed using the assumed mode method. More realistic boundary conditions, which represent the balance of moments and shear forces separately, at the ends of each link, are used for the dynamic model development of the system. A computationally efficient multi-stage MPC algorithm with guaranteed stability is developed as well. This algorithm is used by the MPC module to enable real-time implementation of the overall scheme. A fuzzy knowledge base for tuning the MPC controller is developed based on analysis, computer simulations and experimental testing of the prototype flexible-link manipulator system (FLMS). A fuzzy tuner is designed based on this fuzzy knowledge base. The performance of the developed IMPC scheme is evaluated using computer simulations and experiments of the prototype FLMS. The results show that IMPC can more effectively control the motion of a flexible link robot manipulator when compared with conventional MPC.
Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate

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Md, Salleh Salihatun. "Active intelligent control of vibration of flexible plate structures." Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538085.

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Pessu, Ruth A. "Intelligent modelling and control of a flexible link manipulator." Thesis, University of Wolverhampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307841.

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Wong, P. C. "Flexible intelligent robot vision system for the confectionery industry." Thesis, University of Huddersfield, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383499.

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Mansour, Mohammad Ahmad Chaudhry Ghulam M. "A generalized simulation model for flexible manufacturing system." Diss., UMK access, 2005.

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Thesis (Ph. D.)--School of Computing and Engineering and Dept. of Mathematics. University of Missouri--Kansas City, 2005.
"A dissertation in engineering and mathematics." Advisor: Ghulam Chaudhry. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed June 26, 2006. Includes bibliographical references (leaves 341-346 ). Online version of the print edition.

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Ozpeynirci, Selin. "Allocation And Tooling Decisions In Flexible Manufacturing Systems." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12609161/index.pdf.

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In this thesis, we consider a capacity allocation problem in flexible manufacturing systems. We assume limited time and tool magazine capacities on the Computer Numerically Controlled (CNC) machines. We have a set of operations that have to be assigned to the machines and each operation requires a set of tools to be processed. Our problem is to allocate the available capacity of the CNC machines to operations and their required tools. We consider two problems in this study: maximizing the total weight of operations where there are a limited number of tools of each type available and maximizing total weight minus total tooling cost where the tools can be used or purchased at a cost. We model the problems as Integer Linear Programs and show that they are NP-hard in the strong sense. For the total weight problem, we propose upper bounds, branch and bound algorithm for exact solutions and several heuristics for approximate solutions. For the bicriteria problem, we use Lagrangean relaxation technique to obtain lower and upper bounds. Our computational results have revealed that all solution approaches give satisfactory results in reasonable times.

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Kean, Thomas Maxwell. "Supervisory computer control of a flexible manufacturing cell." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27892.

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A combined software and hardware package has been developed which coordinates the activities of a Unimation PUMA 560 industrial robot and an ORAC CNC training lathe in a Flexible Manufacturing Cell environment under the supervision of a DEC VAX 11/750 computer. The hardware component is used to provide an intermediate interface between the VAX 11/750 software and the standard manual controls of the ORAC lathe. The interface to the PUMA robot is strictly software oriented and makes use of the Supervisor communication protocol provided by the robot's VAL II controller. The software package has been designed as a hierarchial, multi-tasking system to facilitate modular development and a logical division of labour. The hierarchy consists of three main levels, with the individual machine controllers providing the lowest level. At the middle layer is a number of subprocesses which execute on the VAX 11/750 and are each responsible for the direct supervision of one machine controller. This supervision involves both sending commands and receiving status messages in the native language of the individual controllers. At the top layer of the hierarchy is a single process which is responsible for the overall coordination of the workcell activities. Each subtask in the hierarchy communicates with its vertical neighbours through a series of communication protocols and command vocabularies developed for that purpose. Each subtask is also provided with a structured interface to the operator's console. This interface is implemented by a separate VAX process that provides a status window environment for each machine that is active in the cell, but also intercepts text messages and prompts so that they may be displayed to the operator one at a time. Two different software packages have been developed for the top layer of the hierarchy. The ORCAM package is dedicated to the task of automatically manufacturing turned components from a CAD database. The FMC package provides a flexible interface to each of the supported machines and may be used to supervise any number of user-defined tasks.
Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate

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Zhang, Wenle. "Scalable deadlock avoidance algorithms for flexible manufacturing systems." Ohio : Ohio University, 2000. http://www.ohiolink.edu/etd/view.cgi?ohiou1179862449.

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Dissertations / Theses on the topic 'Intelligent and Flexible Manufacturing'

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